Intracranial internal carotid artery stenosis.

The advent of EC/IC Bypass surgery has focused attention on selected patients who might benefit from this innovative procedure. There is a poverty of natural history data pertaining to all such lesions. Two centres (Memphis, Tennessee and London, Ontario) pooled their resources to carry out a retrospective review of 58 patients with angiographically-proven intracranial internal carotid artery stenosis. Only 33% of the patients were alive and free from subsequent cerebral vascular events at the end of the mean follow-up of 30 months. Forty-three percent of the patients died during follow-up: 36% due to stroke and 44% because of cardiac disease. Forty-three percent of the patients suffered cerebral vascular events during the follow-up period: there were 17 strokes (29%) including 9 fatal strokes. The incidence of ipsilateral stroke was 19%; 65% of the strokes were appropriate to the stenotic intracranial carotid lesion under study. The annual ipsilateral stroke rate for patients with this lesion was 7.6% per year. This lesion detected on angiography is indicative of severe atheroma, and carries a serious risk of death due to ischemic heart disease or stroke.